From 3371802fba3f7be4465f8a5e5777d43d556676ef Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 31 Mar 2023 18:52:33 -0700 Subject: accel/tcg: Fix jump cache set in cpu_exec_loop Assign pc and use store_release to assign tb. Fixes: 2dd5b7a1b91 ("accel/tcg: Move jmp-cache `CF_PCREL` checks to caller") Reported-by: Weiwei Li Reviewed-by: Peter Maydell Signed-off-by: Richard Henderson --- accel/tcg/cpu-exec.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) (limited to 'accel') diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index c815f2d..8370c92 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -257,7 +257,7 @@ static inline TranslationBlock *tb_lookup(CPUState *cpu, target_ulong pc, if (cflags & CF_PCREL) { /* Use acquire to ensure current load of pc from jc. */ - tb = qatomic_load_acquire(&jc->array[hash].tb); + tb = qatomic_load_acquire(&jc->array[hash].tb); if (likely(tb && jc->array[hash].pc == pc && @@ -272,7 +272,7 @@ static inline TranslationBlock *tb_lookup(CPUState *cpu, target_ulong pc, return NULL; } jc->array[hash].pc = pc; - /* Use store_release on tb to ensure pc is written first. */ + /* Ensure pc is written first. */ qatomic_store_release(&jc->array[hash].tb, tb); } else { /* Use rcu_read to ensure current load of pc from *tb. */ @@ -971,18 +971,27 @@ cpu_exec_loop(CPUState *cpu, SyncClocks *sc) tb = tb_lookup(cpu, pc, cs_base, flags, cflags); if (tb == NULL) { + CPUJumpCache *jc; uint32_t h; mmap_lock(); tb = tb_gen_code(cpu, pc, cs_base, flags, cflags); mmap_unlock(); + /* * We add the TB in the virtual pc hash table * for the fast lookup */ h = tb_jmp_cache_hash_func(pc); - /* Use the pc value already stored in tb->pc. */ - qatomic_set(&cpu->tb_jmp_cache->array[h].tb, tb); + jc = cpu->tb_jmp_cache; + if (cflags & CF_PCREL) { + jc->array[h].pc = pc; + /* Ensure pc is written first. */ + qatomic_store_release(&jc->array[h].tb, tb); + } else { + /* Use the pc value already stored in tb->pc. */ + qatomic_set(&jc->array[h].tb, tb); + } } #ifndef CONFIG_USER_ONLY -- cgit v1.1